The field of the invention is pedestrian signal indicators and the invention relates more particularly to pedestrian signal indicators which are provided with a tactile output so that a person of limited vision can determine when it is time to cross the signal controlled intersection.
The most metropolitan areas in the United States have intersections controlled by traffic lights. These intersections are also equipped with walk/don""t walk signals to make it safe for pedestrians to cross the street. Such walk/don""t walk signals are invariably equipped to provide a visual walk/don""t walk signal. For persons of limited vision, such lighted signals are often of no value. For this reason various pedestrian signal systems have been developed which provide an audible or tactile signal that persons of impaired vision can use.
One such system is shown in U.S. Pat. No. 2,461,448. A button 14 either projects or is flush with the casing, depending on whether the traffic lights are red or green. This provides a tactile indication to a blind person as to whether the light is red or green. Two alternate versions show a pair of push buttons so that a blind person feeling for a signal can always obtain a positive indication and avoid the danger of feeling the top of the casing and assuming that the button is depressed, whereas he may not be feeling the correct spot. A third version causes the button to extend if the power goes out, thereby indicating an unsafe condition. An audible buzzer is also shown.
U.S. Pat. No. 4,590,474 shows a street crossing signal which includes a pair of handrails which are oriented in the direction of the crossing so that the blind person can orient himself in a desired direction for crossing the street. A vibrator is included in the handrail so, when the lights at the crosswalk are in a designation inviting pedestrian crossing, the vibration means in the handrail is activated.
In U.S. Pat. No. 4,851,836, the pedestrian crossing system includes a tactile tone generator. The tone is generated in an area located immediately above the push button switch. U.S. Pat. No. 5,103,223 utilizes a street crossing signal which includes means for vibrating a direction arrow extending through the panel 23. The depressing of a push button 24 initiates the crossing signal sequence.
While the above-described systems assist a visually impaired pedestrian, further simplification, which makes it easier for the pedestrian to become informed when the walk indicator is active, is needed.
It is the object of the present invention to provide an accessible signal system to assist visually impaired persons to cross a signal controlled intersection which system is intuitively simple to use and highly reliable and provides information currently not provided by other devices on the market.
The present invention is for an accessible pedestrian signal system which includes a push button station, which includes means for generating a tactile signal and also audible information. The system has a push button frame mounted at or near each crosswalk at the intersection. A flexible diaphragm is mounted on the frame and supports a push button which is used to initiate a pedestrian crossing signaling sequence. Means are provided for vibrating the push button so that a pedestrian may receive a tactile response while touching the push button to convey a cross/don""t cross indication. Preferably, the pressing of the push button flexes a piezo-electric switch to transmit a signal to the control circuit for the intersection. Also preferably, a coil causes a plunger to vibrate and the movement of the plunger is transmitted to the push button. Also preferably, the push button is mounted on a flexible diaphragm over an opening in the frame. The diaphragm allows limited movement of the button and a backing plate holds the diaphragm and the button together. The backing plate is designed to contact the frame as a hand stop when the button is impacted, thus protecting the internal mechanism of the device. The use of the diaphragm and the limited movement provides a push button assembly with a high degree of vandal resistance yet allows the button to both move and vibrate to indicate a walk cycle.